General Message Scanning Order

When Deep Discovery Email Inspector receives an email message, Deep Discovery Email Inspector applies the scan settings on messages in the following order:

  • Approved Senders list

  • SMTP traffic throttling

  • Sender filtering (Email Reputation Services (ERS), Directory Harvest Attack (DHA), and Bounce Attack)

  • Domain-based message authentication (SPF, DKIM, and DMARC)

  • Message-level exceptions

  • Policy rules:

    • Content filtering rules

    • Data loss prevention (DLP) rules

    • Antispam protection rules

    • Advanced threat protection rules

Note:

When you configure the Approved Senders and Blocked Senders lists for sender filtering/authentication, Deep Discovery Email Inspector applies settings to check the senders in the following order:

  • For SMTP traffic throttling:

    • Approved Senders list (IP address)

    • Blocked Senders list (user-defined IP address)

    • SMTP traffic throttling (IP address)

    • Approved Senders list (email address)

    • Blocked Senders list (user-defined email address)

    • SMTP traffic throttling (email address)

  • For sender filtering (ERS, DHA, and Bounce Attack) and domain-based message authentication (SPF, DKIM, and DMARC):

    • Approved Senders list (IP address and email address)

    • Blocked Senders list (user-defined IP address and email address)

    • Sender filtering (ERS, DHA, Bounce Attack)

    • Domain-based message authentication (SPF, DKIM, and DMARC)